Fluids

Fluids

Wave height reasonable decay quantity

    • Tlinxo
      Subscriber

      I have simulated a progressive, small amplitude wave (wave length=6m,wave height=0.0304m, water depth=1m, calculating zone length=60m, and damping zone set at 48m) by Fluent VOF in k-wSST turbulent model. And I have transfer the waveform into Tecplot.

      it looks a little decay , I'd like to know how can we determined the wave is "physically decay" or "artificially decay"? How can we know this decay is reasonable?

      From now on I found out every value of amplitude at the wave crests and wave trough, and calculated the differences between them and the setting wave amplitude. And transfer the value into percentages.

      But I can't decide how low is the difference, error of the percentage is physically decay for waves without artificial decay cause meshing or else.

    • DrAmine
      Ansys Employee
      These things are called dispersion and diffusion error: dispersion in the frequency or wave length and diffusion in the height. I cannot tell you if this not phyiscal but I am sure the numerics and espcially the resolution has to do something with it.
      Key points:

      1/Wave profiles depends on the domain extend especially above the free surface level.
      2/<= 1.5 of wavelength to be considered on top
      3/minimum resolution 20 cells per height and 200 cells per wavelength.

      You did not mention anything about outflow conditions and beaching.
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